2.1 Invoking Octave from the Command Line

Normally, Octave is used interactively by running the program `octave' without any arguments. Once started, Octave reads commands from the terminal until you tell it to exit.

You can also specify the name of a file on the command line, and Octave will read and execute the commands from the named file and then exit when it is finished.

You can further control how Octave starts by using the command-line options described in the next section, and Octave itself can remind you of the options available. Type `octave --help' to display all available options and briefly describe their use (`octave -h' is a shorter equivalent).

2.1.1 Command Line Options

Here is a complete list of all the command line options that Octave accepts.

--debug

-d

Enter parser debugging mode. Using this option will cause Octave's parser to print a lot of information about the commands it reads, and is probably only useful if you are actually trying to debug the parser.

--echo-commands

-x

Echo commands as they are executed.

--eval code

Evaluate code and exit when done unless --persist is also specified.

--exec-path path

Specify the path to search for programs to run. The value of path specified on the command line will override any value of OCTAVE_EXEC_PATH found in the environment, but not any commands in the system or user startup files that set the built-in variable EXEC_PATH.

--help

-h

-?

Print short help message and exit.

--image-path path

Specify the path to search for images. The value of path specified on the command line will set the value of IMAGE_PATH found in the environment.

--info-file filename

Specify the name of the info file to use. The value of filename specified on the command line will override any value of OCTAVE_INFO_FILE found in the environment, but not any commands in the system or user startup files that use the info_file function.

--info-program program

Specify the name of the info program to use. The value of program specified on the command line will override any value of OCTAVE_INFO_PROGRAM found in the environment, but not any commands in the system or user startup files that use the info_program function.

--interactive

-i

Force interactive behavior. This can be useful for running Octave via a remote shell command or inside an Emacs shell buffer. For another way to run Octave within Emacs, see Emacs Octave Support.

--no-history

-H

Disable command-line history.

--no-init-file

Don't read the `~/.octaverc' or `.octaverc' files.

--no-line-editing

Disable command-line editing.

--no-site-file

Don't read the site-wide `octaverc' file.

--norc

-f

Don't read any of the system or user initialization files at startup. This is equivalent to using both of the options --no-init-file and --no-site-file.

--path path

-p path

Specify the path to search for function files. The value of path specified on the command line will override any value of OCTAVE_PATH found in the environment, but not any commands in the system or user startup files that set the internal load path through one of the path functions.

--persist

Go to interactive mode after --eval or reading from a file named on the command line.

--silent

--quiet

-q

Don't print the usual greeting and version message at startup.

--traditional

--braindead

For compatibility with MATLAB, set initial values for user-preferences to the following values

PS1 = ">> " PS2 = "" beep_on_error = true crash_dumps_octave_core = false default_save_options = "-mat-binary" fixed_point_format = true history_timestamp_format_string = "%%-- %D %I:%M %p --%%" page_screen_output = false print_empty_dimensions = false

and disable the following warnings

Octave:fopen-file-in-path Octave:function-name-clash Octave:load-file-in-path

--verbose

-V

Turn on verbose output.

--version

-v

Print the program version number and exit.

file

Execute commands from file. Exit when done unless --persist is also specified.

Octave also includes several built-in variables that contain information about the command line, including the number of arguments and all of the options.

Built-in Function: argv ()

Return the command line arguments passed to Octave. For example, if you invoked Octave using the command

octave --no-line-editing --silent

argv would return a cell array of strings with the elements --no-line-editing and --silent.

If you write an executable Octave script, argv will return the list of arguments passed to the script. See section Executable Octave Programs, for an example of how to create an executable Octave script.

Built-in Function: program_name ()

Return the last component of of the value returned by program_invocation_name.
See also: program_invocation_name.

Built-in Function: program_invocation_name ()

Return the name that was typed at the shell prompt to run Octave.

If executing a script from the command line (e.g., octave foo.m) or using an executable Octave script, the program name is set to the name of the script. See section Executable Octave Programs, for an example of how to create an executable Octave script.
See also: program_name.

Here is an example of using these functions to reproduce Octave's command line.

printf ("%s", program_name ());
arg_list = argv ();
for i = 1:nargin
  printf (" %s", arg_list{i});
endfor
printf ("\n");

See section Index Expressions, for an explanation of how to properly index arrays of strings and substrings in Octave, and See section Defining Functions, for information about the variable nargin.

2.1.2 Startup Files

When Octave starts, it looks for commands to execute from the files in the following list. These files may contain any valid Octave commands, including function definitions.

octave-home/share/octave/site/m/startup/octaverc

Where octave-home is the directory in which all of Octave is installed (the default is `/usr/local'). This file is provided so that changes to the default Octave environment can be made globally for all users at your site for all versions of Octave you have installed. Some care should be taken when making changes to this file, since all users of Octave at your site will be affected.

octave-home/share/octave/version/m/startup/octaverc

Where octave-home is the directory in which all of Octave is installed (the default is `/usr/local'), and version is the version number of Octave. This file is provided so that changes to the default Octave environment can be made globally for all users for a particular version of Octave. Some care should be taken when making changes to this file, since all users of Octave at your site will be affected.

~/.octaverc

This file is normally used to make personal changes to the default Octave environment.

.octaverc

This file can be used to make changes to the default Octave environment for a particular project. Octave searches for this file in the current directory after it reads `~/.octaverc'. Any use of the cd command in the `~/.octaverc' file will affect the directory that Octave searches for the file `.octaverc'.

If you start Octave in your home directory, commands from from the file `~/.octaverc' will only be executed once.

A message will be displayed as each of the startup files is read if you invoke Octave with the --verbose option but without the --silent option.

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